《ROS 2多协议传输控制器》使用 micro-ROS 协议+以太网DHCP方式接入 ROS 系统

[小鱼]

《ROS 2多协议传输控制器》使用 micro-ROS 协议+以太网DHCP方式接入 ROS 系统

开始前准备：

硬件：

1. 传输控制板*1
2. Type-B电源线*1
3. 网线*1
4. 带网口的电脑或者USB网卡*1
5. 9~28V电源

软件：

1. 安装Ubuntu的系统*1
2. 安装好ROS2 Humble以上版本ROS系统

1. micro-ROS Agent 和 消息接口下载与构建

在主目录下创建，ros2_transmission_ws 目录及子目录src（其他目录也可以）

mkdir  -p ~/ros2_transmission_ws/src

下载源码

cd ~/ros2_transmission_ws/src
git clone http://github.fishros.org/https://github.com/fishros/micro-ROS-Agent -b humble
git clone http://github.fishros.org/https://github.com/fishros/robot_interfaces
git clone http://github.fishros.org/https://github.com/micro-ROS/micro_ros_msgs.git -b humble

构建工作空间

cd ~/ros2_transmission_ws/
colcon build
---
Starting >>> micro_ros_agent
Starting >>> robot_interfaces                 
Finished <<< robot_interfaces [6.76s]                         
[Processing: micro_ros_agent]                             
--- stderr: micro_ros_agent                                
正克隆到 'xrceagent'...
切换到一个新分支 'ros2'
HEAD 目前位于 c25243c Enable Domain Override on Reference and XML Participant (#351)
CMake Warning (dev) at /usr/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
  The package name passed to `find_package_handle_standard_args` (tinyxml2)
  does not match the name of the calling package (TinyXML2).  This can lead
  to problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  cmake/modules/FindTinyXML2.cmake:40 (find_package_handle_standard_args)
  /opt/ros/humble/share/fastrtps/cmake/fastrtps-config.cmake:51 (find_package)
  CMakeLists.txt:153 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

---
Finished <<< micro_ros_agent [56.9s]

Summary: 2 packages finished [58.9s]
  1 package had stderr output: micro_ros_agent

看到：Summary: 2 packages finished [58.9s] 就表示构建成功了，中间的警告请忽略。

2.完成硬件连接

这种连接方式的特点是，通过网线将雷达和电脑(控制卡)直连，优点是稳定。

连接方式：

电脑<----Type-B|USB线----->控制板USB口
电脑<----网线----->路由器<----网线----->控制板网口
电源---->控制板电源口

3.查看电脑IP地址

使用ifconfig查看所有网卡

ifconfig 
---
enx4ce173422378: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.2  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::915b:c170:f24c:844c  prefixlen 64  scopeid 0x20<link>
        ether 4c:e1:73:42:23:78  txqueuelen 1000  (以太网)
        RX packets 38  bytes 3850 (3.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 81  bytes 12357 (12.3 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0


lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (本地环回)
        RX packets 879222  bytes 758350473 (758.3 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 879222  bytes 758350473 (758.3 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

可以看到我这里有一个USB网卡：enx4ce173422378 是以太网（你的可能不是这个名字，请仔细辨别）

目前已经自动DHCP分配了一个IP地址：192.168.0.2 这个就是服务器的IP地址。

4.使用配置助手修改配置

打开配置助手，扫描配置，确认如下选项的值，若不是，请手动修改。

配置项	描述	设置值
transport_mode	传输模式（例如以太网静态IP配置协议）	eth_dhcp
server_ip	服务器的IP地址	你的电脑ip(这里是192.168.0.2)
server_port	服务器的端口号	8888

传输模式我们这里采用 eth_dhcp ，动态分配IP模式，并设置micro-ROS的服务器的IP地址为你的电脑ip地址。

设置完成后请手动或者点击配置助手的重启设备进行重启。

5.运行agent,接收消息

进入到工作空间，运行agent

cd ~/ros2_transmission_ws/
source install/setup.bash
ros2 run micro_ros_agent micro_ros_agent  udp4 --port 8888 -v4
---
[1719815438.222600] info     | UDPv4AgentLinux.cpp | init                     | running...             | port: 8888
[1719815438.222750] info     | Root.cpp           | set_verbose_level        | logger setup           | verbose_level: 4
[1719815496.167443] info     | Root.cpp           | create_client            | create                 | client_key: 0x4786978B, session_id: 0x81
[1719815496.167490] info     | SessionManager.hpp | establish_session        | session established    | client_key: 0x4786978B, address: 192.168.0.5:47138
[1719815496.183027] info     | ProxyClient.cpp    | create_participant       | participant created    | client_key: 0x4786978B, participant_id: 0x000(1)
[1719815496.185031] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x000(2), participant_id: 0x000(1)
[1719815496.186523] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x4786978B, publisher_id: 0x000(3), participant_id: 0x000(1)
[1719815496.188218] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x4786978B, datawriter_id: 0x000(5), publisher_id: 0x000(3)
[1719815496.190136] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x001(2), participant_id: 0x000(1)
[1719815496.191351] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x4786978B, subscriber_id: 0x000(4), participant_id: 0x000(1)
[1719815496.192840] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x4786978B, datareader_id: 0x000(6), subscriber_id: 0x000(4)
[1719815496.194586] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x002(2), participant_id: 0x000(1)
[1719815496.195990] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x4786978B, publisher_id: 0x001(3), participant_id: 0x000(1)
[1719815496.197459] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x4786978B, datawriter_id: 0x001(5), publisher_id: 0x001(3)
[1719815496.199148] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x003(2), participant_id: 0x000(1)
[1719815496.200651] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x4786978B, subscriber_id: 0x001(4), participant_id: 0x000(1)
[1719815496.202154] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x4786978B, datareader_id: 0x001(6), subscriber_id: 0x001(4)
[1719815496.203922] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x004(2), participant_id: 0x000(1)
[1719815496.205361] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x4786978B, publisher_id: 0x002(3), participant_id: 0x000(1)
[1719815496.206800] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x4786978B, datawriter_id: 0x002(5), publisher_id: 0x002(3)
[1719815496.208490] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x4786978B, topic_id: 0x005(2), participant_id: 0x000(1)
[1719815496.209961] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x4786978B, subscriber_id: 0x002(4), participant_id: 0x000(1)
[1719815496.211445] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x4786978B, datareader_id: 0x002(6), subscriber_id: 0x002(4)

看到上面的日志就表示连接成功了，接着就可以尝试订阅IO状态话题，打开新的终端，输入如下命令：

cd ~/ros2_transmission_ws/
source install/setup.bash
ros2 topic echo /read_io
---
analog: []
digital:
- 1
- 1
- 1
- 1
---
analog: []
digital:
- 1
- 1
- 1
- 1
---
...

可以看到这里每帧输出了四个数据，是四个输入IO的状态，这个话题默认以10Hz进行发布，发布频率可以修改。

使用 ros2 topic list 可以查看控制器节点可以支持的话题。

话题名称	消息接口	订阅/发布
/write_485	robot_interfaces/msg/RawUInt8	订阅
/write_can	robot_interfaces/msg/CanFrame	订阅
/write_io	robot_interfaces/msg/WriteIO	订阅
/read_485	robot_interfaces/msg/RawUInt8	发布
/read_can	robot_interfaces/msg/CanFrame	发布
/read_io	robot_interfaces/msg/ReadIO	发布

关于每个话题如何使用，可以参考例程篇介绍。

6. 设置固定IP地址

因为控制板要将数据发送到电脑端，如果电脑的IP采用DHCP动态分配，一旦分配到其他IP都会造成通信异常。解决方法是通过在路由器后台设置IP地址和MAC地址绑定，这样就可以保证每次分配的IP一致。